Insoftware engineering, adesign marker is a technique of documentingdesign choices insource code using theMarker Interface pattern. Marker interfaces have traditionally been limited to those interfaces intended for explicit,runtime verification (normally viainstanceof). A design marker is a marker interface used todocument a design choice. InJava programs the design choice is documented in the marker interface'sJavadoc documentation.
Many choices made at software design time cannot be directly expressed in today's implementation languages likeC# and Java. These design choices (known by names likeDesign Pattern,Design Contract,Refactoring,Effective Programming Idioms,Blueprints, etc.) must be implemented via programming andnaming conventions, because they go beyond the built-in functionality of production programming languages. The consequences of this limitation conspire over time to erode design investments as well as to promote a false segregation between the designer and implementer mindsets.
Two independent proposals recognize these problems and give the same basic strategies for tackling them. Until now, the buddingexplicit programming movement has been linked to the use of an experimental Java research tool called ELIDE. The Design Markers technique requires only standardJavadoc-like tools to garner many of the benefits ofExplicit Programming.